Vehicle peripheral observation device using cameras and an emphasized frame

ABSTRACT

Provided is a device whereby the position of an obstacle can be perceived on a monitor without compromising the effectiveness of displaying an overhead image on the monitor. An overhead image generating unit generates an overhead image from images captured using plural cameras, and the overhead image is displayed in an auxiliary display area of a monitor. When an obstacle detection part detects an obstacle in proximity to a vehicle, a specified information output unit emphasizes the display of a frame in the outer side of a divided area of the overhead image that contains the obstacle. Touching the auxiliary display area with a finger or the like during this emphasized display causes the captured image of the obstacle to be enlarged and displayed in the auxiliary display area.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/636,080, filed Sep. 19, 2012, which is a 371 National Stage entry ofPCT/JP2011/052135, filed Feb. 2, 2011, which claims benefit to JapanesePatent Application No. 2010-0723235, filed Mar. 26, 2010. The entiredisclosures of the prior applications are considered part of thedisclosure of the accompanying continuation application, and are herebyincorporated by reference.

TECHNICAL FIELD

The present invention relates to a vehicle peripheral observationdevice, and more specifically relates to a technique for displaying animage captured by a camera on a monitor and enabling a driver torecognize an obstacle from the captured image displayed on the monitor.

BACKGROUND ART

As a vehicle peripheral observation device configured as describedabove, Patent Document 1 discloses a processing format in which anoverhead image of the vehicle periphery is generated from imagescaptured using a plurality of cameras and displayed on a monitor (thedisplay in the document), the overhead image divides the peripheral areaof the vehicle into a plurality of areas, and when a user selects any ofthese areas with a touch panel, an overhead image of the selected areais enlarged and displayed on the monitor.

Patent Document 1 also discloses that the area displaying the overheadimage and the area displaying the enlarged image in the monitor are setseparately, and it is possible to make a selection for the enlargedimage between a mode of enlarging the overhead image and a mode ofenlarging the image captured using the camera that images the selectedarea (the camera-view image).

As a vehicle peripheral observation device configured as describedabove, Patent Document 2 discloses a processing format in which anoverhead image of the vehicle periphery is generated from imagescaptured using a plurality of cameras and displayed on a monitor (thedisplay device in the document), and when an obstacle is detected by anobstacle sensor provided to the vehicle, an image including part of thevehicle and the obstacle is extracted to generate a caution image, andthe caution image is displayed in a position in the overhead imageequivalent to the position of the obstacle.

PRIOR ART DOCUMENTS Patent Documents

[Patent Document 1] Japanese Laid-open Patent Application No.2009-239674

[Patent Document 2] Japanese Laid-open Patent Application No.2006-131166

DISCLOSURE OF THE INVENTION Problems that the Invention is Intended toSolve

When the vehicle is moved to a parking position or when the vehicletraverses a road surface in which an obstacle or a parked vehicle ispresent, the positional relationship between the vehicle and theobstacle or the like in the vehicle's proximity must be confirmed. Inthe techniques disclosed in Patent Document 1 and Patent Document 2, theconditions of all areas of the vehicle periphery, including areas in thedriver's blind spot, can be perceived from the overhead image.

However, when an obstacle is displayed on the monitor during an overheaddisplay, the obstacle is difficult to visually confirm because of itssmall display size, and it is also difficult to perceive the gap betweenthe vehicle and the obstacle, leaving room for improvement.

As a countermeasure to this inconvenience, in the technique disclosed inPatent Document 1, the area indicated by the driver is enlarged anddisplayed on the monitor, and factors such as the positionalrelationship between the obstacle and the vehicle body can be easilyconfirmed by the enlarged image. However, because the plurality of areasdisplayed on the monitor are comparatively small in size, and moreover,because there must be an operation for the driver to select and indicatethe area containing the obstacle from the plurality of areas, it can betroublesome and there is room for improvement.

In Patent Document 2, when an obstacle is detected, a new window isautomatically opened to display the obstacle in the area containing theobstacle, and the positional relationship between the obstacle and thevehicle body can be perceived from the display of this window. However,when the driver already perceives the positional relationship of theobstacle, the window display sometimes causes an inconvenience in thatthe nearby road surface or the like is covered by the window and theroad surface conditions cannot be visually confirmed.

An object of the present invention is to rationally configure a devicewhereby the position of an obstacle can be perceived withoutcompromising the effectiveness of displaying an overhead image on themonitor.

Means for Solving the Problems

The present invention comprises a plurality of cameras for imaging areasincluding a road surface of a vehicle periphery, an image processor fordisplaying the images captured using the plurality of cameras on amonitor, and obstacle-detecting means for detecting an obstacle in thevehicle periphery;

the image processor having overhead-image-generating means forgenerating an overhead image looking down on the vehicle periphery fromabove from the images captured using the plurality of cameras anddisplaying the resulting image in an overhead image display area of themonitor, the overhead image display area being divided and managed as aplurality of divided areas, and specified information output unit that,when an obstacle is detected by the obstacle-detecting unit, emphasizesthe display of a frame in the outer periphery of the divided areacontaining the obstacle detected by the obstacle-detecting unit fromamong the plurality of divided areas, and displaying the position of thedetected obstacle on the monitor.

According to this configuration, when an overhead image is displayed onthe monitor and an obstacle is detected by the obstacle-detecting unit,the display of the frame in the outer periphery of the divided areacontaining the obstacle is emphasized by the specified informationoutput unit. This emphasized display enables the area containing theobstacle to be perceived from among the plurality of divided areas.

As a result, the device is configured in a manner such that the positionof the obstacle can be perceived without compromising the effectivenessof displaying an overhead image on the monitor.

In the present invention, the emphasized display may be either anincrease in the brightness of the frame or a switching of the frame to adifferent hue.

According to this configuration, increasing the brightness of the frameor switching the hue of the frame makes it possible to easily specifythe divided area to which the frame corresponds.

In the present invention, the monitor may have a touch panel in thedisplay surface, and may also have enlarged display unit for enlargingto the size of the enlarged display area, in a state where theemphasized display is being performed, the display of an image of thedivided area in the monitor where the emphasized display is beingperformed when touching of the overhead image display area is sensed inthe touch panel during the emphasized display.

According to this configuration, even without an operation of selectinga divided screen and touching with a finger, an image including theobstacle can be enlarged to the size of the enlarged display area merelyby touching a finger or the like to the overhead image display area, andthe obstacle can be confirmed.

In the present invention, the enlarged display unit may perform aprocess of setting the overhead image displayed in the divided areawhere the emphasized display is performed as an image to be enlarged,setting an enlarged display area in which the image to be enlarged isdisplayed as enlarged, generating a plurality of intermediate images inwhich the image to be enlarged will be an intermediate size between thesize of the divided area and the size of the enlarged display area, andsequentially displaying the intermediate images beginning with thesmallest size.

According to this configuration, the area containing the obstacle can beperceived visually due to the overhead image of the divided area beingenlarged. An overhead image of the same size as the divided area isdisplayed as being enlarged gradually up to the size of the enlargeddisplay area, it being simple to perceive which divided area's overheadimage has been enlarged.

In the present invention, the enlarged display unit may perform aprocess of setting the image captured using the camera that has imagedthe emphasized-display divided area as an image to be enlarged, settingan enlarged display area in which the image to be enlarged is displayedas enlarged, generating a plurality of intermediate images in which theimage to be enlarged will be an intermediate size between the size ofthe divided area and the size of the enlarged display area, andsequentially displaying the intermediate images beginning with thesmallest size.

According to this configuration, the area containing the obstacle can beperceived visually as seen from the camera's viewpoint, due to theenlarging of the image captured using the camera that images the areacontaining the obstacle. A captured image of the same size as thedivided area is displayed as being enlarged gradually up to the size ofthe enlarged display area, and which divided area the enlarged capturedimage corresponds to can be easily perceived.

In the present invention, the enlarged display unit may display theoverhead image in the overhead image display area instead of theenlarged display produced by the enlarged display unit when theobstacle-detecting unit has switched to a state of not detectingobstacles.

According to this configuration, when the vehicle body has completelypassed through the area containing the obstacle, the original overheadimage is then displayed in the overhead image display area, and a stateof perceiving the entire state of the vehicle periphery is resumedwithout any manual operation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view showing an overview of the configuration of thevehicle;

FIG. 2 is a partially cutaway perspective view showing the configurationof the vehicle;

FIG. 3 is a block circuit diagram of the control system;

FIG. 4 is a flowchart of the vehicle periphery observation process;

FIG. 5 is a continuous depiction of the process of enlarging theoverhead image of a divided area to the auxiliary display area;

FIG. 6 is a continuous depiction of the process of enlarging theoverhead image of a divided area to the auxiliary display area;

FIG. 7 is a continuous depiction of the process of enlarging theoverhead image of a divided area to the primary display area; and

FIG. 8 is a continuous depiction of the process of enlarging theoverhead image of a divided area to the entire screen of the monitor.

BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of the present invention will be described below withreference to the accompanying drawings.

In the present embodiment, provided is a vehicle peripheral observationdevice for generating an overhead image in the format of looking down onthe periphery of a vehicle 1 from above from images captured using aplurality of cameras provided to the vehicle 1, and displaying theoverhead image on a monitor 21. Particularly, when the vehicleperipheral observation device detects an obstacle X in the vicinity ofthe vehicle, the overhead image displayed on the monitor 21 is dividedinto a plurality of parts, divided areas D1 to D4 are set, an emphasisdisplay is performed for specifying the divided areas D1 to D4 includingthe obstacle X, and control is executed for displaying an enlarged imageof the area containing the obstacle X on the monitor 21 (hereinbelowreferred to as an enlarge process). The format and configuration of suchcontrol are described hereinbelow.

[Basic Configuration]

The vehicle 1 as a passenger vehicle comprises left and right frontwheels 2 and left and right rear wheels 3, as shown in FIGS. 1 and 2. Aleft front door 4 and a right front door 5 that can open and close byhinges are provided to positions in the front of the vehicle 1, a leftrear door 6 and a right rear door 7 that can open and close in a slidingmanner are provided to positions in the rear of the vehicle 1, and ahatchback type back door 8 is provided in the rear end of the vehicle 1.

A driver seat 13, a passenger seat 14, and a plurality of rear seats 15are provided inside the interior of the vehicle 1. A steering wheel 16is provided in a position in front of the driver seat 13, and a panelhaving gauges is disposed in the front part of the steering wheel. Atthe foot of the driver seat 13 are disposed an acceleration pedal 17 anda brake pedal 18 for operating braking devices BK of the front wheels 2and rear wheels 3 and exerting braking force on the front wheels 2 andrear wheels 3, and a shift lever 19 for implementing a speed change isdisposed in the side of the driver seat 13.

The monitor 21, which has a touch panel 21T formed in a surface display,is provided in proximity to the driver seat 13 and in a position in thetop part of a console. The monitor 21 is a liquid crystal device havinga backlight. As shall be apparent, the monitor may also use a plasmadisplay or a CRT. The touch panel 21T is configured as apressure-sensitive or electrostatic command input device for outputtingthe contact position of a finger or the like as location data. Thehousing 21H of the monitor 21 is also provided with a speaker 22, butthe speaker 22 may also be provided in another location such as theinner side of a door. The monitor 21 can also serve as a display deviceof a navigation system, but a monitor that is used solely for a vehicleperipheral observation display may also be used.

The left front door 4 is provided with a left side mirror 23, and theright front door 5 is provided with a right side mirror 24. The leftside mirror 23 is provided with a left side camera 25, and the rightside mirror 24 is provided with a right side camera 26. The front end ofthe vehicle 1 is provided with a front camera 27, and the rear end ofthe vehicle 1 is provided with a rear camera 28.

Particularly, the imaging directions of the left side camera 25 andright side camera 26 are oriented downward, and part of the vehicle 1and the road surface are included in the imaging area. The imagingdirections of the front camera 27 and rear camera 28 are oriented at adownward slant, and part of the vehicle 1 and the road surface areincluded in the imaging area.

These cameras, used as imaging devices, are digital cameras equippedwith charge coupled devices (CODs), CMOS image sensors (CISs), or otherimaging elements, and the cameras output imaged information as videoinformation in real time. The cameras are ensured a wide field of visionby being provided with wide-angle lenses.

The monitor 21 is used to display navigation information duringnavigation mode control, but images captured by the rear camera 28 aredisplayed when the shift lever 19 has been operated to the reverseposition. Particularly, the image captured by the rear camera 28 is animage in which left and right are interchanged by left-right mirrorreflection, and the content displayed in the monitor 21 can be visuallyconfirmed with the same sensation as that of using the rearview mirrorto confirm the rearward view.

The front part of the vehicle is provided with a power steering unit PSfor transmitting the rotational operation force of the steering wheel 16to the front wheels 2 and performing drive steering. The front part ofthe vehicle is also provided with an engine E, and a speed changemechanism T consisting of a torque converter, a CVT, or the like forchanging the speed of motive power from the engine E and transmitting itto the front wheels 2. Switching between forward and reverse andchanging the travel speed of the speed change mechanism T are performedby operating the shift lever 19.

The vehicle 1 is provided with various sensors for detecting the drivingoperation and the movement state of the vehicle 1. More specifically,the operating system of the steering wheel 16 is provided with asteering sensor S16 for measuring the steering operation direction (thesteering direction) and the operated amount (steered amount). Theoperating system of the shift lever 19 is provided with a shift positionsensor S19 for distinguishing the shift position. The operating systemof the acceleration pedal 17 is provided with an acceleration sensor S17for measuring the operated amount, and the operating system of the brakepedal 18 is provided with a brake sensor S18 for detecting whether ornot the brake pedal is being operated.

In the proximity of the rear wheels 3, there is provided a photointerrupter or pickup type movement distance sensor S3 so as to measurethe movement amount of the vehicle 1 from the rotation amount of therear wheels 3. The movement distance sensor S3 may be one that acquiresthe movement amount from the rotation amount of the transmission systeminside the speed change mechanism T. The movement distance sensor S3 maymeasure the rotation amount of the front wheels 2. Furthermore, themovement distance sensor S3 may be configured so as to detect themovement amount and steering amount of the vehicle 1 from imageprocessing of the captured image of the front camera 27 or the rearcamera 28.

[Control Configuration]

An ECU 30 as the vehicle peripheral observation device of the presentinvention is disposed in the middle of the vehicle 1. The ECU 30comprises an interface consisting of a sensor input interface 31 and acommunication interface 32, and also comprises an image output module 33and an audio output module 34, as shown in FIG. 3.

The ECU 30 comprises a microprocessor, a digital signal processor (DSP),or another processing system for processing information obtained via theinterface, the processing results are outputted from the image outputmodule 33 to the monitor 21, and audio information is outputted from theaudio output module 34 to the speaker 22.

The ECU 30 comprises a navigation controller 35 for implementingnavigation mode control, a map data preservation part 36 for sending mapinformation to the navigation controller 35, a parking assistancecontroller 37 for implementing parking assistance mode control, anobstacle detector 38 (an example of the obstacle-detecting unit) forsensing an obstacle X in the proximity of the vehicle, and an imageprocessor 39 for implementing vehicle peripheral observation processing.

The navigation controller 35 acquires the vehicle position indicated bylatitude information and longitude information from a GPS unit 41 duringtravel, acquires map data corresponding to the vehicle position, anddisplays the position and data on the monitor 21. The navigationinformation leading to the destination is displayed on the monitor 21,and leading information is outputted in audio from the speaker 22. Themap data preservation part 36 performs a process of sending the map datacorresponding to the vehicle position to the navigation controller 35.

The parking assistance controller 37 displays an estimated route image Y(see FIG. 6(a)), which leads the vehicle 1 to a parking position,superimposed over the image displayed on the monitor 21 by the imageprocessor 39. The driver can easily lead the vehicle 1 into the targetparking position by performing the steering operation on the basis ofthe estimated route image Y displayed on the monitor 21.

The image processor 39 disposes a primary display area 21A and anauxiliary display area 21B (an example of the overhead image displayarea) in the layout shown in FIG. 5(a) on the monitor 21 in the vehicleperipheral observation process, and displays a camera icon 21C showingthe camera that captured the image of this area in a position in the topof the primary display area 21A.

The image processor 39 comprises overhead-image-generating unit 39A forgenerating an overhead image in the format of looking down on thevehicle 1 from above from the images captured by the plurality ofcameras previously described; divided area management unit 39B fordividing and managing the overhead image displayed on the monitor 21into a plurality of divided areas D1 to D4; specified information outputunit 39C for displaying an emphasized frame F corresponding to thedivided area D containing the obstacle X from among a plurality offrames F1 to F4, the frame F being information specifying which area ofthe plurality of divided areas D1 to D4 displays the obstacle X; enlargemode setting unit 39D for setting an image to be enlarged and anenlarged display area; and enlarged display unit 39E for enlarging theimage to be enlarged to the enlarged display area. As shown in FIG.5(a), the divided area D1 and the divided area D2 correspond to the leftand right sides of the front part of the vehicle, while the divided areaD3 and the divided area D4 correspond to the left and right sides of therear part of the vehicle. Similarly, the frames F1 to F4 correspond tothe divided areas D1 to D4 as shown in the drawings. The divided area Dis used as a broader term for the divided areas D1 to D4, and the frameF is used as a broader term for the frames F1 to F4.

The ECU 30 is configured from an electronic circuit, and some or theentirety of the interface or output system may be included in thiselectronic circuit. The ECU 30 has either an electronic circuitconstituting a processing system, or a storage part configured by amemory, register, or the like as a separate component; and informationis inputted and outputted by a database, an address bus, a control bus,and other components.

The sensor input interface 31 receives input of driving operationinformation and information for detecting the movement state from thesteering sensor S16, the shift position sensor S19, the accelerationsensor S17, the brake sensor S18, and the movement distance sensor S3.

The communication interface 32 conducts communication between the powersteering unit PS, the speed change mechanism T, the braking devices BK,and the GPS unit 41 via communication lines. Furthermore, thecommunication interface 32 acquires information from the touch panel21T, the left side camera 25, the right side camera 26, the front camera27, and the rear camera 28.

The image output module 33 outputs images to the monitor 21, and theaudio output module 34 outputs audio to the speaker 22.

[Control Format]

A format of the vehicle peripheral observation display process is shownin the flowchart of FIG. 4, and the content displayed in the monitor 21when this process is executed is shown in FIGS. 5 to 8.

In other words, when the shift lever 19 is placed in the forwardposition in a state in which the vehicle peripheral observation processhas been selected, the image captured using the front camera 27 isdisplayed on the primary display area 21A as shown in FIG. 5(a). Thecamera icon 21C, which shows that the image is the image captured usingthe front camera 27, is displayed in a position in the top part of theprimary display area 21A, and an overhead image is displayed in theauxiliary display area 21B. Conversely, when the shift lever 19 isplaced in the reverse position, the image captured using the rear camera28 is displayed in the primary display area 21A as shown in FIG. 6(a).The camera icon 21C, which shows that the image is the image capturedusing the rear camera 28, is displayed in a position in the top part ofthe primary display area 21A, and an overhead image is displayed in theauxiliary display area 21B (steps #101 and #102).

A specific format of the process is that when the shift lever 19 hasbeen placed in the forward position, the image captured using the frontcamera 27 is displayed in the primary display area 21A. When the shiftlever 19 has been placed in the rear position, the image captured usingthe rear camera 28 is acquired, a mirror reflection image interchangingthe left and right of this captured image is generated, and the image isdisplayed on the monitor 21.

The overhead image displayed in the auxiliary display area 21B isgenerated as a single overhead image disposed on the road surface by theoverhead-image-generating unit 39A acquiring the images captured usingthe left side camera 25, the right side camera 26, the front camera 27,and the rear camera 28, converting the images to projected images in theformat of looking down from above, and mapping the projected images inan imaginary plane in a position encompassing the vehicle image.

The overhead image displayed in this manner is divided and managed asfour divided areas D1 to D4 so as to be sectioned by sectioning lines Lshown as dashed lines. The sectioning lines L shown in the drawing arenot displayed on the screen, but the process format may be set so thatthe sectioning lines L are displayed on the screen.

Particularly, the overhead image displayed in the auxiliary display area21B is generated from the images captured using four cameras, but therespective overhead images of the four divided areas D1 to D4 sectionedby the sectioning lines L are generated by combining the images capturedusing two cameras. In other words, overlapping areas W (see FIG. 1) inthe images captured using two cameras are formed in outer positions atthe front and rear corners of the vehicle 1, and the images are combinedso that the border regions in the overlapping areas W do not stand out.When the overhead image combined in this manner is set as the image tobe enlarged, the overhead image is enlarged to the size of the enlargeddisplay area.

When the shift lever 19 has been placed in the reverse position, it ispossible to execute parking assistance control as well, and when parkingassistance control is thus executed, an estimated route image Y isdisplayed superimposed over the primary display area 21A and theauxiliary display area 21B as shown in FIG. 6(a).

The estimated route image Y represents the route the vehicle 1 willtraverse when the vehicle 1 is reversed with the current steeringamount, and the estimated route image Y is generated in an imaginaryplane coinciding with the road surface with a sense of perspectivecorresponding to the captured image displayed on the monitor 21. Theestimated route image is formed in a frame by a pair of vehicle widthlines Ya forming a width equal to the width of the vehicle 1, and aplurality of distance lines Yb showing the positions the vehicle 1 willreach upon reversing in the set amount.

The obstacle detector 38 previously described is configured as softwarefor extracting, as an obstacle X, a three-dimensional object thatproduces a parallax from the images of the overlapping areas W thatoverlap in the imaging areas of the left side camera 25, the right sidecamera 26, the front camera 27, and the rear camera 28. A summary of theprocess for extracting the three-dimensional object can be described asfollows. In other words, the image of an overlapping area W in theimages captured using two cameras is projected and converted to animaginary plane having the same background, and the two images that havebeen projected and converted are superimposed in a positionalrelationship such that the same backgrounds of the images coincide. Theimage that does not coincide during this superimposing is thethree-dimensional object, the three-dimensional object is estimated tobe an obstacle X, and the position of the obstacle X is specified.

The overlapping area W of the imaging area of the two cameras could alsobe in a blind spot for the driver, and it is rational that only theobstacle X in this area be the object of detection. The vehicle may havefour or more cameras in order to enlarge the area of detection for theobstacle X. Furthermore, the obstacle detector 38 may be configured assoftware for detecting the obstacle X by an optical-flow technique.

Particularly, the obstacle detector 38 may comprise an ultrasonic sensoror other obstacle sensors in a plurality of locations in the vehicle 1,such as the front end and rear end. Configuring the obstacle detector 38using obstacle sensors in order to detect obstacles X in this mannermakes it possible to detect obstacles X in the entire periphery aroundthe vehicle 1.

When an obstacle X is detected by the obstacle detector 38, andspecifically when, among the divided areas D1 to D4, the obstacle X isin the divided area D2 as shown in FIG. 5, the divided area D2 (thedivided area D that includes the detected obstacle X) is indicated, andthe display of the frame F2 in the outer periphery of the divided areaD2 is emphasized (shown in hatching in the drawing). At the same time,the color tone of the divided area D2 containing the obstacle X isvaried, and a warning sound is outputted from the speaker 22 (steps #103and 104). The color tone of D2 need not be varied. In this case, it isacceptable to vary the color tone of only the intermediate image.

In this process, the display is emphasized in the divided area D2containing the obstacle X from among the divided areas D1 to D4 managedby the divided area management unit 39B, by the specified informationoutput unit 39C increasing the brightness of the frame F2, increasingthe chroma, or varying the frame to a different hue. In addition to thisemphasized display, the display of the frame F2 may be varied so as toblink. One possibility for the process of varying the color tone of thedivided area D2 containing the obstacle X to a different color tone is aprocess of increasing the brightness or reducing the brightness of oneof the three primary colors, blue (B), of the pixels of the image in thedivided area D2, for example. Furthermore, the warning sound outputtedfrom the speaker 22 need not be an electronic sound, and may be a wordedmessage.

Next, when there is sensed a touch operation of the driver's fingers orthe like touching the auxiliary display area 21B, the touch operation isa trigger for the image (the overhead image or image captured using thecamera) of the divided area D2 already indicated to be used as the imageto be enlarged, and an enlarge process is performed for enlarging theimage to be enlarged to the enlarged display area (steps #105 and #106).

In this process, the enlarged display unit 39E executes an enlargeprocess in accordance with the enlarge mode set by the enlarge modesetting unit 39D. An image to be enlarged and an enlarged display areaare set in this enlarge mode. Set as the image to be enlarged is eitherthe overhead image displayed in the divided area D2 containing theobstacle X, or the image captured by one of the cameras that has imagedthe obstacle X (the image as viewed from the camera). One of thefollowing modes is set: a normal enlarge mode for setting the auxiliarydisplay area 21B as the enlarged display area, a separate screen enlargemode for setting the primary display area 21A as the enlarged displayarea, or an entire screen enlarge mode for setting the entire screen ofthe monitor 21 as the enlarged display area.

The procedure for setting the enlarge mode may consist of a mode settingscreen being displayed on the monitor 21 and the mode being set inadvance manually.

[Control Format: Normal Enlarge Mode]

When the enlarge process is performed in normal enlarge mode, theenlarged display unit 39E sets the image to be enlarged (the overheadimage of the divided area D in the drawing), sets the auxiliary displayarea 21B shown in FIGS. 5 and 6 as the enlarged display area, and setsan enlarged display trajectory (not shown) between the divided areaD2-D3 (meaning D2 in FIG. 5 and divided area D3 in FIG. 6) and theenlarged display area (the auxiliary display area 21B).

Next, the image of the divided area D2-D3 (an overhead image) isenlarged as shown in FIGS. 5(b) and 6(b), thereby generating anintermediate image M slightly larger in size than the divided areaD2-D3, and the intermediate image M is displayed superimposed over theoverhead image of the auxiliary display area 21B in a position coveringthe entire divided area D2-D3 (the divided area D set by the presence ofthe obstacle X) which acts as a display origin point. The image of thedivided area D2-D3 (an overhead image) is then immediately furtherenlarged as shown in FIGS. 5(c) and 6(c), whereby an intermediate imageM of a larger size is formed and displayed in a position conforming tothe enlarged display trajectory. In this case, a process is performedfor deleting the previously displayed intermediate image M anddisplaying the next intermediate image M, and in normal enlarge mode,the next intermediate image M is displayed superimposed over theoverhead image of the auxiliary display area 21B in a positionalrelationship of covering the entire intermediate image M that waspreviously displayed.

As the size of the intermediate image M is gradually moved along theenlarged display trajectory, intermediate images M of progressivelylarger sizes are displayed. The enlarged display is executed for aduration of about 0.5 seconds or 1 second, for example, and ultimatelyan enlarged image consisting of an enlargement of the image (overheadimage) of the divided area D2-D3 fills up the area of the auxiliarydisplay area 21B as shown in FIGS. 5(d) and 6(d). An area icon 21D isthen displayed in the corner of the enlarged image, thereby completingthe enlarge process. Particularly, the area icon 21D is set to a shapeshowing the area imaged by the camera and a size that does not overlapthe road surface (a size that overlaps the vehicle image), and theoriginal position of the image to be enlarged can be recognized from thearea icon 21D.

[Control Format: Separate Screen Enlarge Mode]

When the enlarge process is performed in separate screen enlarge mode,the enlarged display unit 39E sets the image to be enlarged (theoverhead image of the divided area D3 in FIG. 7), sets the primarydisplay area 21A as the enlarged display area, and sets an enlargeddisplay trajectory (not shown) between the divided area D3 and theenlarged display area (the primary display area 21A). In this controlformat as well, the color tone of the divided area D3 containing theobstacle X is varied and the display of the frame F3 in the outerperiphery is emphasized (shown in hatching in the drawing).

Next, the image (an overhead image) of the divided area D3 is enlargedas shown in FIG. 7(a), thereby generating an intermediate image Mslightly larger in size than the divided area D3, and the intermediateimage M is displayed superimposed in a position covering much of thedisplay area D3 (the divided area D set by the presence of the obstacleX) which acts as a display origin point. The image of the divided areaD3 (an overhead image) is then immediately further enlarged as shown inFIG. 7(b), whereby an intermediate image M of a larger size is formedand displayed in a position conforming to the enlarged displaytrajectory.

As the size of the intermediate image M is gradually moved along theenlarged display trajectory, intermediate images M of progressivelylarger sizes are displayed. The enlarged display is executed for aduration of about 0.5 seconds or 1 second, for example, and ultimatelyan enlarged image consisting of an enlargement of the image (overheadimage) of the divided area D3 fills up the area of the primary displayarea 21A as shown in FIG. 7(c). An area icon 21D is then displayed inthe corner of the enlarged image, thereby completing the enlargeprocess. Particularly, the area icon 21D has a shape showing the areaimaged by the camera, and the original position of the image to beenlarged can be recognized from the area icon 21D.

In separate screen enlarge mode, because the enlarged display area (theprimary display area 21A) and the divided area D3 have different aspectratios, there is a deformation of the enlarged image in which theoverhead image of the divided area D3 fills up the area of the primarydisplay area 21A. The display may also have the top and bottom ends ofthe enlarged image trimmed off while the area displaying the obstacle Xremains.

[Control Format: Entire Screen Enlarge Mode]

When the enlarge process is performed in entire screen enlarge mode, theenlarged display unit 39E sets the image to be enlarged (the overheadimage of the divided area D3 in FIG. 8), sets the display area of themonitor 21 as the enlarged display area, and sets an enlarged displaytrajectory (not shown) between the divided area D3 and the enlargeddisplay area (the display area of the monitor 21). In this controlformat as well, the color tone of the divided area D3 containing theobstacle X is varied and the display of the frame F3 in the outerperiphery is emphasized (shown in hatching in the drawing).

Next, the image (an overhead image) of the divided area D3 is enlargedas shown in FIG. 8(a), thereby generating an intermediate image Mslightly larger in size than the divided area D3, and the intermediateimage M is displayed superimposed in a position covering much of thedisplay area D3 (the divided area D set by the presence of the obstacleX) which acts as a display origin point. The image of the divided areaD3 (an overhead image) is then immediately further enlarged as shown inFIG. 8(b), whereby an intermediate image M of a larger size is formedand displayed in a position conforming to the enlarged displaytrajectory.

As the size of the intermediate image M is gradually moved along theenlarged display trajectory, intermediate images M of progressivelylarger sizes are displayed. The enlarged display is executed for aduration of about 0.5 seconds or 1 second, for example, and ultimatelyan enlarged image consisting of an enlargement of the image (overheadimage) of the divided area D3 fills up the display area of the monitor21 as shown in FIG. 8(c). An area icon 21D is then displayed in thecorner of the enlarged image, thereby completing the enlarge process.Particularly, the area icon 21D has a shape showing the area imaged bythe camera, and the original position of the image to be enlarged can berecognized from the area icon 21D.

In entire screen enlarge mode, because the enlarged display area (thedisplay area of the monitor 21) and the divided area D3 have differentaspect ratios, there is a deformation of the enlarged image in which theoverhead image of the divided area D3 fills up the display area of themonitor 21. The display may also have the top and bottom ends of theenlarged image trimmed off while the area displaying the obstacle Xremains.

Regardless of which enlarge mode the enlarge process is performed in,the image is enlarged in a format of moving the display position of theintermediate image M along the enlarged display trajectory using theposition of the divided area D as an origin point (the position of thecorner of the intermediate image M does not move in normal enlarge modeof FIGS. 5 and 6), and enlargement in a zoomed-in format is achievedwhile the position of the original image being enlarged (the position ofthe divided area D) is clarified. It is then possible to recognize whicharea the enlarged image belongs to, from the format of the area icon 21Ddisplayed in the corner of the enlarged image or from the displayposition of the area icon 21D.

A superimposed display is implemented by performing the process forforming intermediate images M in a movie layer when the enlarge processis performed in either enlarge mode, and while this superimposed displayis in effect, changes in the positional relationship between the vehicle1 and the obstacle X can be displayed in real time using either overheadimages or captured images. As will be described next, the process isfinished by deleting the enlarged image and deleting the video layerimage even when the original display is to be restored.

Next, when there is sensed a touch operation of the driver's fingers orthe like touching any area of the monitor 21, or when a state is reachedin which no obstacle X is detected by the obstacle detector 38, theenlarged image is deleted and the sequence transitions to the process ofstep #101, thereby resuming control in which a captured image isdisplayed in the primary display area 21A of the monitor 21 and anoverhead image is displayed in the auxiliary display area 21B (steps#107 to #109).

The vehicle peripheral observation display process is then continueduntil a selection is made for ceasing control (step #110).

Thus, in the present invention, when the vehicle 1 is being led into aparking position, or when the vehicle 1 is traversing a road surface inwhich a fence, a parked vehicle, or another obstacle X is present, aimage captured by a camera is displayed in the primary display area 21Aof the monitor 21, and an overhead image is displayed in the auxiliarydisplay area 21B of the monitor 21. The positional relationship betweenthe vehicle 1 and an obstacle X in proximity to the vehicle can therebybe confirmed even when the obstacle X is in the driver's blind spot.

When the vehicle is in proximity to an obstacle X, an emphasized displayis performed, increasing the brightness of the frame F among the framesF1 to F4 that corresponds to the outer periphery of the divided area Dcontaining the obstacle X among the divided areas D1 to D4 of theoverhead image. At the same time as this display, a display is performedfor varying the color tone of the divided area D containing the obstacleX and a warning sound is outputted from the speaker 22, whereby the areacontaining the obstacle X can be perceived.

By touching the auxiliary display area 21B with the finger or the likein this state of being able to perceive the position of the obstacle X,the divided area D containing the obstacle X among the divided areas D1to D4 is enlarged to the enlarged display area, and the positionalrelationship between the obstacle X and the vehicle 1 can be confirmedin the enlarged image.

Particularly, when the image of any of the plurality of divided areas D1to D4 is enlarged to the enlarged display area, display is performed ina format such that, using the divided area D containing the obstacle Xas an origin point, a plurality of intermediate images M of differentsizes are moved sequentially along the enlarged display trajectory so asto transition from smaller sized images to larger sized images. Byenlarging in this manner, an enlargement is implemented in a format ofzooming in while clarifying the position of the original image beingenlarged (the position of the divided area D containing the obstacle X).

As a result of the enlarged display of either the overhead image of thearea containing the obstacle X or the image captured using the camerathat imaged the obstacle X, the positional relationship between theobstacle X and the vehicle 1 can be perceived from the enlarged image,and the vehicle 1 can be moved in a manner that avoids contact with theobstacle X.

[Other Embodiments]

Other than the embodiments described above, the present invention mayalso be configured in the following manner.

(a) When the overhead image is divided into and managed as a pluralityof divided areas D, it may be divided into and managed as a number ofdivisions other than four, such as two or six divisions. Theconfiguration may allow the user to set the number of divisions asdesired. When the division is a large number, the proximity of theobstacle X to local areas in the periphery of the vehicle 1 can beconfirmed, and the region of the obstacle can be enlarged and displayed.

(b) The operation for executing the enlarge process of enlarging theimage of the divided area D containing the obstacle X may be setting thecontrol format so that the enlarge process is initiated even if a fingeror the like touches any location of the display area of the monitor 21,or the operation may be an enlarge button or the like for initiating theenlarge process, displayed on the monitor 21. Similarly, a designatedbutton for ending the enlarged display may be displayed on the monitor21.

(c) When an image to be enlarged is set in the enlarge process by theenlarge mode setting unit 39D and when an obstacle X is detected infront of the vehicle 1 (when there is an obstacle X in a divided area Din front of the vehicle), an overhead image is set as the image to beenlarged. Conversely, when an obstacle X is detected behind the vehicle1 (when there is an obstacle X in a divided area D behind the vehicle),an image captured by a camera is set as the image to be enlarged.

This is because when there is an obstacle X in front of the vehicle 1,the driver will sometimes lean out of the vehicle to visually confirmthe obstacle, and it is effective for the obstacle X thus visuallyconfirmed to be displayed as seen from a different direction than anobstacle X that could be seen by the driver, which is made possible bysetting an overhead image as the image to be enlarged. When there is anobstacle X behind the vehicle 1, the obstacle often cannot be seen bythe driver, and it is effective for the image to be enlarged to be acaptured image that gives the sense of looking directly at the imagecaptured by a camera.

(d) When an image to be enlarged is set in the enlarge process by theenlarge mode setting unit 39D, and when the configuration is such thatthe height of the obstacle X can be measured by the obstacle detector 38and the height exceeds a set value (when it is comparatively high), theimage captured by a camera is set as the image to be enlarged so thatthe height can be recognized. Conversely, when the height is less thanthe set value (when it is comparatively low), an overhead image is setas the image to be enlarged because there is no need to recognize theheight. The height of the obstacle X can be easily perceived byselecting the image to be enlarged in this manner.

(e) In the previous other embodiments (c) and (d), when a image capturedby a camera is used as the image to be enlarged and when the operateddirection of the steering wheel 16 is determined to be the forwarddirection of the vehicle 1 and a direction approaching the obstacle X, aimage captured using a side camera (the left side camera 25 or the rightside camera 26) is set as the image to be displayed. When the forwarddirection of the vehicle 1 is determined to be a direction going awayfrom the obstacle X, an image captured by a camera in an end of thevehicle 1 (the front camera 27 or the rear camera 28) is set as theimage to be displayed.

By selecting the camera that acquires the captured image on the basis ofthe steering direction in this manner, changes in the relativepositional relationship between the obstacle X and the vehicle 1 caneasily be perceived from the image captured using a side camera (theleft side camera 25 or the right side camera 26), even when the vehicle1 has moved somewhat in a direction approaching the obstacle X. When thevehicle 1 moves in a direction going away from the obstacle X, a widearea in the forward direction of the vehicle 1 can be displayed on themonitor 21 and the forward direction can be confirmed from an imagecaptured by a camera in an end of the vehicle 1.

(f) When it is detected that “the overhead image display area (theauxiliary display area) has been touched,” it may either be a detectionof a touching state change from a state of no touching of the touchpanel 21T (the overhead image area) to a state of touching, or adetection of a state change from a state of a finger or the liketouching the touch panel 21T (the overhead image area) to a state of thefinger or the like taken away.

INDUSTRIAL APPLICABILITY

The present invention can be utilized in an entire vehicle having animage processing system for generating an overhead image from the imagescaptured using a plurality of cameras provided to the vehicle anddisplaying the overhead image on a monitor.

KEY

1 Vehicle

21 Monitor

21B Overhead image display area (auxiliary display area)

21T Touch panel

25 Camera (left side camera)

26 Camera (right side camera)

27 Camera (front camera)

39 Image processor

39A Overhead-image-generating unit

39C Specified information output unit

39E Enlarged display unit

D Divided area

f Frame

M Intermediate image

X Obstacle

The invention claimed is:
 1. A vehicle peripheral observation devicecomprising: a plurality of cameras for imaging an area including a roadsurface of a vehicle periphery, an image processor for displaying theimages captured using the plurality of cameras on a monitor; andobstacle-detecting unit for detecting an obstacle in the vehicleperiphery, wherein the image processor is configured to show a displayarea for the captured images to be displayed on the monitor and providea plurality of frames dividing the display area into sections, whereinthe image processor is configured to emphasize at least one of theplurality of frames near an area where the obstacle that has beendetected by the obstacle-detecting unit and included in the display areais present, wherein the emphasized frame has at least two line segmentsin a right angle arrangement and each line segment is displayed in apart of an outer rim of the section in the display area, and wherein theemphasized frame does not form an enclosed area.
 2. The vehicleperipheral observation device according to claim 1, wherein theemphasized display increases the brightness of the frame or switches ahue of the frame to a different hue.
 3. The vehicle peripheralobservation device according to claim 1, wherein each of the pluralityof frames is displayed in an outer periphery of the display area.